Coffee is a kind of drinks prepared by extracting and processing coffee beans of a coffee tree. The coffee tree is a dicotyledon belonging to rubiaceae. Although about 40 kinds of coffee trees grow in Africa and tropical regions of Asia, coffea Arabica and coffea Canephora are commonly called two parent lines of coffee. The coffee tree blossoms (white color) about two years after planting, and bears red or yellow fruits (beans, cherries) about three years after planting.
The coffee trees are harvested in a tropical region between south latitude 25° C. and north latitude 25° about the Equator, the region of which is called a coffee belt or a coffee zone. Arabica coffee has a picky cultivating conditions, grows under an average temperature of 15˜24° C., and requires rainy season and dry season for growth. Furthermore, the Arabic coffee prefers ash soil abundant in organic substances and good in drainage, adequate sun shine and a high land above 800 m.
Meantime, heavy rains and strong wind are not good for the Arabic coffee. Robusta coffee may be cultivated as long as a temperature of 24° C.˜30° C. on a high land soil at a latitude under 600 m is maintained.
A seed of the coffee bean peeled off with husk, flesh, endocarp, and silver skin is called a green bean. Coffee beans are made from the green bean by roasting, and coffee drink is prepared by extracting the green bean substance using water. Consumption of coffee drinks increases at a great pace, and kinds of coffee drinks are gradually diversified in response to consumer tastes.
Meantime, harvest of coffee is greatly influenced by infectious diseases and harmful insects. A first disease may be anthrax. The anthrax is a disease that causes to produce round red spots on the coffee bean, i.e., on the cherry coffee skin, and is a fungus disease generated on the cherry itself.
A second disease is uredinales causing leaf molds which in turn make leaves to wither by generating yellow spots on rear surfaces of coffee tree leaves, and the coffee trees become dead in three years thereafter.
A third one is occurrence of coffee berry borer. The coffee berry borer, the most important coffee pest worldwide, degrades the commodity value of coffee beans by boring from inside of cherry.
A last and fourth disease of black bean phenomenon refers to a phenomenon where defective beans are harvested due to insufficient supply of nutrients and water to the coffee trees at right times. The more the black bean phenomenon occurs, the more the coffee crop decreases as much.
In order to reduce the occurrences of diseases and pests, although researches have been waged to cultivate the coffee trees by using chemical fertilizers, new problems have been raised that the chemical fertilizers play a bad influence on the environment. As a result, researches on environment-friendly seedlings and plant manufacturing methods capable of naturally reducing occurrences of diseases and pests without using chemical fertilizers at all are being made. However, there have been no researches made so far on coffee tree cultivating methods manufacturing coffee beans capable of reinforcing immunity levels and containing saponine.